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authorBenjamin Berg <benjamin.berg@intel.com>2023-06-18 21:49:53 +0300
committerJohannes Berg <johannes.berg@intel.com>2023-06-19 13:08:28 +0300
commit2481b5da9c6b2ee1fde55a1c29eb2ca377145a10 (patch)
treef49772e06e54a53a60f042e875b56aa6af19299b /net/wireless
parentdc92e54c30c4bc9d30e674a445dfe1afdca991cf (diff)
downloadlinux-2481b5da9c6b2ee1fde55a1c29eb2ca377145a10.tar.xz
wifi: cfg80211: handle BSS data contained in ML probe responses
The basic multi-link element within an multi-link probe response will contain full information about BSSes that are part of an MLD AP. This BSS information may be used to associate with a link of an MLD AP without having received a beacon from the BSS itself. This patch adds parsing of the data and adding/updating the BSS using the received elements. Doing this means that userspace can discover the BSSes using an ML probe request and request association on these links. Signed-off-by: Benjamin Berg <benjamin.berg@intel.com> Signed-off-by: Gregory Greenman <gregory.greenman@intel.com> Link: https://lore.kernel.org/r/20230618214436.29593bd0ae1f.Ic9a67b8f022360aa202b870a932897a389171b14@changeid [swap loop conditions smatch complained about] Signed-off-by: Johannes Berg <johannes.berg@intel.com>
Diffstat (limited to 'net/wireless')
-rw-r--r--net/wireless/scan.c361
1 files changed, 354 insertions, 7 deletions
diff --git a/net/wireless/scan.c b/net/wireless/scan.c
index f0b4d7671d17..2e7787b0828b 100644
--- a/net/wireless/scan.c
+++ b/net/wireless/scan.c
@@ -1979,6 +1979,7 @@ cfg80211_get_bss_channel(struct wiphy *wiphy, const u8 *ie, size_t ielen,
struct cfg80211_inform_single_bss_data {
struct cfg80211_inform_bss *drv_data;
enum cfg80211_bss_frame_type ftype;
+ struct ieee80211_channel *channel;
u8 bssid[ETH_ALEN];
u64 tsf;
u16 capability;
@@ -1986,7 +1987,12 @@ struct cfg80211_inform_single_bss_data {
const u8 *ie;
size_t ielen;
- /* Set for nontransmitted BSSIDs */
+ enum {
+ BSS_SOURCE_DIRECT = 0,
+ BSS_SOURCE_MBSSID,
+ BSS_SOURCE_STA_PROFILE,
+ } bss_source;
+ /* Set if reporting bss_source != BSS_SOURCE_DIRECT */
struct cfg80211_bss *source_bss;
u8 max_bssid_indicator;
u8 bssid_index;
@@ -2014,22 +2020,31 @@ cfg80211_inform_single_bss_data(struct wiphy *wiphy,
(drv_data->signal < 0 || drv_data->signal > 100)))
return NULL;
- channel = cfg80211_get_bss_channel(wiphy, data->ie, data->ielen,
- drv_data->chan, drv_data->scan_width);
+ if (WARN_ON(data->bss_source != BSS_SOURCE_DIRECT && !data->source_bss))
+ return NULL;
+
+ channel = data->channel;
+ if (!channel)
+ channel = cfg80211_get_bss_channel(wiphy, data->ie, data->ielen,
+ drv_data->chan,
+ drv_data->scan_width);
if (!channel)
return NULL;
memcpy(tmp.pub.bssid, data->bssid, ETH_ALEN);
tmp.pub.channel = channel;
tmp.pub.scan_width = drv_data->scan_width;
- tmp.pub.signal = drv_data->signal;
+ if (data->bss_source != BSS_SOURCE_STA_PROFILE)
+ tmp.pub.signal = drv_data->signal;
+ else
+ tmp.pub.signal = 0;
tmp.pub.beacon_interval = data->beacon_interval;
tmp.pub.capability = data->capability;
tmp.ts_boottime = drv_data->boottime_ns;
tmp.parent_tsf = drv_data->parent_tsf;
ether_addr_copy(tmp.parent_bssid, drv_data->parent_bssid);
- if (data->source_bss) {
+ if (data->bss_source != BSS_SOURCE_DIRECT) {
tmp.pub.transmitted_bss = data->source_bss;
ts = bss_from_pub(data->source_bss)->ts;
tmp.pub.bssid_index = data->bssid_index;
@@ -2088,7 +2103,7 @@ cfg80211_inform_single_bss_data(struct wiphy *wiphy,
rdev_inform_bss(rdev, &res->pub, ies, data->drv_data);
- if (data->source_bss) {
+ if (data->bss_source == BSS_SOURCE_MBSSID) {
/* this is a nontransmitting bss, we need to add it to
* transmitting bss' list if it is not there
*/
@@ -2197,6 +2212,7 @@ cfg80211_parse_mbssid_data(struct wiphy *wiphy,
.tsf = tx_data->tsf,
.beacon_interval = tx_data->beacon_interval,
.source_bss = source_bss,
+ .bss_source = BSS_SOURCE_MBSSID,
};
const u8 *mbssid_index_ie;
const struct element *elem, *sub;
@@ -2365,6 +2381,332 @@ ssize_t cfg80211_defragment_element(const struct element *elem, const u8 *ies,
}
EXPORT_SYMBOL(cfg80211_defragment_element);
+struct cfg80211_mle {
+ struct ieee80211_multi_link_elem *mle;
+ struct ieee80211_mle_per_sta_profile
+ *sta_prof[IEEE80211_MLD_MAX_NUM_LINKS];
+ ssize_t sta_prof_len[IEEE80211_MLD_MAX_NUM_LINKS];
+
+ u8 data[];
+};
+
+static struct cfg80211_mle *
+cfg80211_defrag_mle(const struct element *mle, const u8 *ie, size_t ielen,
+ gfp_t gfp)
+{
+ const struct element *elem;
+ struct cfg80211_mle *res;
+ size_t buf_len;
+ ssize_t mle_len;
+ u8 common_size, idx;
+
+ if (!mle || !ieee80211_mle_size_ok(mle->data + 1, mle->datalen - 1))
+ return NULL;
+
+ /* Required length for first defragmentation */
+ buf_len = mle->datalen - 1;
+ for_each_element(elem, mle->data + mle->datalen,
+ ielen - sizeof(*mle) + mle->datalen) {
+ if (elem->id != WLAN_EID_FRAGMENT)
+ break;
+
+ buf_len += elem->datalen;
+ }
+
+ res = kzalloc(struct_size(res, data, buf_len), gfp);
+ if (!res)
+ return NULL;
+
+ mle_len = cfg80211_defragment_element(mle, ie, ielen,
+ res->data, buf_len,
+ WLAN_EID_FRAGMENT);
+ if (mle_len < 0)
+ goto error;
+
+ res->mle = (void *)res->data;
+
+ /* Find the sub-element area in the buffer */
+ common_size = ieee80211_mle_common_size((u8 *)res->mle);
+ ie = res->data + common_size;
+ ielen = mle_len - common_size;
+
+ idx = 0;
+ for_each_element_id(elem, IEEE80211_MLE_SUBELEM_PER_STA_PROFILE,
+ ie, ielen) {
+ res->sta_prof[idx] = (void *)elem->data;
+ res->sta_prof_len[idx] = elem->datalen;
+
+ idx++;
+ if (idx >= IEEE80211_MLD_MAX_NUM_LINKS)
+ break;
+ }
+ if (!for_each_element_completed(elem, ie, ielen))
+ goto error;
+
+ /* Defragment sta_info in-place */
+ for (idx = 0; idx < IEEE80211_MLD_MAX_NUM_LINKS && res->sta_prof[idx];
+ idx++) {
+ if (res->sta_prof_len[idx] < 255)
+ continue;
+
+ elem = (void *)res->sta_prof[idx] - 2;
+
+ if (idx + 1 < ARRAY_SIZE(res->sta_prof) &&
+ res->sta_prof[idx + 1])
+ buf_len = (u8 *)res->sta_prof[idx + 1] -
+ (u8 *)res->sta_prof[idx];
+ else
+ buf_len = ielen + ie - (u8 *)elem;
+
+ res->sta_prof_len[idx] =
+ cfg80211_defragment_element(elem,
+ (u8 *)elem, buf_len,
+ (u8 *)res->sta_prof[idx],
+ buf_len,
+ IEEE80211_MLE_SUBELEM_FRAGMENT);
+ if (res->sta_prof_len[idx] < 0)
+ goto error;
+ }
+
+ return res;
+
+error:
+ kfree(res);
+ return NULL;
+}
+
+static bool
+cfg80211_tbtt_info_for_mld_ap(const u8 *ie, size_t ielen, u8 mld_id, u8 link_id,
+ const struct ieee80211_neighbor_ap_info **ap_info,
+ const u8 **tbtt_info)
+{
+ const struct ieee80211_neighbor_ap_info *info;
+ const struct element *rnr;
+ const u8 *pos, *end;
+
+ for_each_element_id(rnr, WLAN_EID_REDUCED_NEIGHBOR_REPORT, ie, ielen) {
+ pos = rnr->data;
+ end = rnr->data + rnr->datalen;
+
+ /* RNR IE may contain more than one NEIGHBOR_AP_INFO */
+ while (sizeof(*info) <= end - pos) {
+ const struct ieee80211_rnr_mld_params *mld_params;
+ u16 params;
+ u8 length, i, count, mld_params_offset;
+ u8 type, lid;
+
+ info = (void *)pos;
+ count = u8_get_bits(info->tbtt_info_hdr,
+ IEEE80211_AP_INFO_TBTT_HDR_COUNT) + 1;
+ length = info->tbtt_info_len;
+
+ pos += sizeof(*info);
+
+ if (count * length > end - pos)
+ return false;
+
+ type = u8_get_bits(info->tbtt_info_hdr,
+ IEEE80211_AP_INFO_TBTT_HDR_TYPE);
+
+ /* Only accept full TBTT information. NSTR mobile APs
+ * use the shortened version, but we ignore them here.
+ */
+ if (type == IEEE80211_TBTT_INFO_TYPE_TBTT &&
+ length >=
+ offsetofend(struct ieee80211_tbtt_info_ge_11,
+ mld_params)) {
+ mld_params_offset =
+ offsetof(struct ieee80211_tbtt_info_ge_11, mld_params);
+ } else {
+ pos += count * length;
+ continue;
+ }
+
+ for (i = 0; i < count; i++) {
+ mld_params = (void *)pos + mld_params_offset;
+ params = le16_to_cpu(mld_params->params);
+
+ lid = u16_get_bits(params,
+ IEEE80211_RNR_MLD_PARAMS_LINK_ID);
+
+ if (mld_id == mld_params->mld_id &&
+ link_id == lid) {
+ *ap_info = info;
+ *tbtt_info = pos;
+
+ return true;
+ }
+
+ pos += length;
+ }
+ }
+ }
+
+ return false;
+}
+
+static void cfg80211_parse_ml_sta_data(struct wiphy *wiphy,
+ struct cfg80211_inform_single_bss_data *tx_data,
+ struct cfg80211_bss *source_bss,
+ gfp_t gfp)
+{
+ struct cfg80211_inform_single_bss_data data = {
+ .drv_data = tx_data->drv_data,
+ .ftype = tx_data->ftype,
+ .source_bss = source_bss,
+ .bss_source = BSS_SOURCE_STA_PROFILE,
+ };
+ struct ieee80211_multi_link_elem *ml_elem;
+ const struct element *elem;
+ struct cfg80211_mle *mle;
+ u16 control;
+ u8 *new_ie;
+ struct cfg80211_bss *bss;
+ int mld_id;
+ u16 seen_links = 0;
+ const u8 *pos;
+ u8 i;
+
+ if (!source_bss)
+ return;
+
+ if (tx_data->ftype != CFG80211_BSS_FTYPE_PRESP)
+ return;
+
+ elem = cfg80211_find_ext_elem(WLAN_EID_EXT_EHT_MULTI_LINK,
+ tx_data->ie, tx_data->ielen);
+ if (!elem || !ieee80211_mle_size_ok(elem->data + 1, elem->datalen - 1))
+ return;
+
+ ml_elem = (void *)elem->data + 1;
+ control = le16_to_cpu(ml_elem->control);
+ if (u16_get_bits(control, IEEE80211_ML_CONTROL_TYPE) !=
+ IEEE80211_ML_CONTROL_TYPE_BASIC)
+ return;
+
+ /* Must be present when transmitted by an AP (in a probe response) */
+ if (!(control & IEEE80211_MLC_BASIC_PRES_BSS_PARAM_CH_CNT) ||
+ !(control & IEEE80211_MLC_BASIC_PRES_LINK_ID) ||
+ !(control & IEEE80211_MLC_BASIC_PRES_MLD_CAPA_OP))
+ return;
+
+ /* length + MLD MAC address + link ID info + BSS Params Change Count */
+ pos = ml_elem->variable + 1 + 6 + 1 + 1;
+
+ if (u16_get_bits(control, IEEE80211_MLC_BASIC_PRES_MED_SYNC_DELAY))
+ pos += 2;
+ if (u16_get_bits(control, IEEE80211_MLC_BASIC_PRES_EML_CAPA))
+ pos += 2;
+
+ /* MLD capabilities and operations */
+ pos += 2;
+
+ /* Not included when the (nontransmitted) AP is responding itself,
+ * but defined to zero then (Draft P802.11be_D3.0, 9.4.2.170.2)
+ */
+ if (u16_get_bits(control, IEEE80211_MLC_BASIC_PRES_MLD_ID)) {
+ mld_id = *pos;
+ pos += 1;
+ } else {
+ mld_id = 0;
+ }
+
+ /* Extended MLD capabilities and operations */
+ pos += 2;
+
+ /* Fully defrag the ML element for sta information/profile iteration */
+ mle = cfg80211_defrag_mle(elem, tx_data->ie, tx_data->ielen, gfp);
+ if (!mle)
+ return;
+
+ new_ie = kmalloc(IEEE80211_MAX_DATA_LEN, gfp);
+ if (!new_ie)
+ goto out;
+
+ for (i = 0; i < ARRAY_SIZE(mle->sta_prof) && mle->sta_prof[i]; i++) {
+ const struct ieee80211_neighbor_ap_info *ap_info;
+ enum nl80211_band band;
+ u32 freq;
+ const u8 *profile;
+ const u8 *tbtt_info;
+ ssize_t profile_len;
+ u8 link_id;
+
+ if (!ieee80211_mle_basic_sta_prof_size_ok((u8 *)mle->sta_prof[i],
+ mle->sta_prof_len[i]))
+ continue;
+
+ control = le16_to_cpu(mle->sta_prof[i]->control);
+
+ if (!(control & IEEE80211_MLE_STA_CONTROL_COMPLETE_PROFILE))
+ continue;
+
+ link_id = u16_get_bits(control,
+ IEEE80211_MLE_STA_CONTROL_LINK_ID);
+ if (seen_links & BIT(link_id))
+ break;
+ seen_links |= BIT(link_id);
+
+ if (!(control & IEEE80211_MLE_STA_CONTROL_BEACON_INT_PRESENT) ||
+ !(control & IEEE80211_MLE_STA_CONTROL_TSF_OFFS_PRESENT) ||
+ !(control & IEEE80211_MLE_STA_CONTROL_STA_MAC_ADDR_PRESENT))
+ continue;
+
+ memcpy(data.bssid, mle->sta_prof[i]->variable, ETH_ALEN);
+ data.beacon_interval =
+ get_unaligned_le16(mle->sta_prof[i]->variable + 6);
+ data.tsf = tx_data->tsf +
+ get_unaligned_le64(mle->sta_prof[i]->variable + 8);
+
+ /* sta_info_len counts itself */
+ profile = mle->sta_prof[i]->variable +
+ mle->sta_prof[i]->sta_info_len - 1;
+ profile_len = (u8 *)mle->sta_prof[i] + mle->sta_prof_len[i] -
+ profile;
+
+ if (profile_len < 2)
+ continue;
+
+ data.capability = get_unaligned_le16(profile);
+ profile += 2;
+ profile_len -= 2;
+
+ /* Find in RNR to look up channel information */
+ if (!cfg80211_tbtt_info_for_mld_ap(tx_data->ie, tx_data->ielen,
+ mld_id, link_id,
+ &ap_info, &tbtt_info))
+ continue;
+
+ /* We could sanity check the BSSID is included */
+
+ if (!ieee80211_operating_class_to_band(ap_info->op_class,
+ &band))
+ continue;
+
+ freq = ieee80211_channel_to_freq_khz(ap_info->channel, band);
+ data.channel = ieee80211_get_channel_khz(wiphy, freq);
+
+ /* Generate new elements */
+ memset(new_ie, 0, IEEE80211_MAX_DATA_LEN);
+ data.ie = new_ie;
+ data.ielen = cfg80211_gen_new_ie(tx_data->ie, tx_data->ielen,
+ profile, profile_len,
+ new_ie,
+ IEEE80211_MAX_DATA_LEN);
+ if (!data.ielen)
+ continue;
+
+ bss = cfg80211_inform_single_bss_data(wiphy, &data, gfp);
+ if (!bss)
+ break;
+ cfg80211_put_bss(wiphy, bss);
+ }
+
+out:
+ kfree(new_ie);
+ kfree(mle);
+}
+
struct cfg80211_bss *
cfg80211_inform_bss_data(struct wiphy *wiphy,
struct cfg80211_inform_bss *data,
@@ -2391,6 +2733,9 @@ cfg80211_inform_bss_data(struct wiphy *wiphy,
return NULL;
cfg80211_parse_mbssid_data(wiphy, &inform_data, res, gfp);
+
+ cfg80211_parse_ml_sta_data(wiphy, &inform_data, res, gfp);
+
return res;
}
EXPORT_SYMBOL(cfg80211_inform_bss_data);
@@ -2549,7 +2894,7 @@ cfg80211_inform_bss_frame_data(struct wiphy *wiphy,
if (!res)
return NULL;
- /* don't do any further MBSSID handling for S1G */
+ /* don't do any further MBSSID/ML handling for S1G */
if (ieee80211_is_s1g_beacon(mgmt->frame_control))
return res;
@@ -2563,6 +2908,8 @@ cfg80211_inform_bss_frame_data(struct wiphy *wiphy,
/* process each non-transmitting bss */
cfg80211_parse_mbssid_data(wiphy, &inform_data, res, gfp);
+ cfg80211_parse_ml_sta_data(wiphy, &inform_data, res, gfp);
+
return res;
}
EXPORT_SYMBOL(cfg80211_inform_bss_frame_data);